Academic Commons

Pandemic influenza: Studying the lessons of history

Next year will mark the 90th anniversary of the great influenza pandemic of 1918, an event widely considered to be one of the greatest natural disasters in human history. Historians estimate that ≥50 million people died worldwide, including >450,000 documented deaths in the United States alone (1). Since then, the 20th century witnessed two more influenza pandemics, although fortunately none comparable in ferocity to the 1918 pandemic (2). Pandemics—epidemics so large that virtually the entire world is affected—have occurred several times in each of the last several centuries. Most virologists therefore believe that it is inevitable that we will experience at least one pandemic in this century, and very likely more. However, if a pandemic were to strike in the near future, it is likely that vaccine would not be available for at least 4-6 months (3). Antivirals, if effective against the pandemic strain, would probably also be in short supply. Few of these measures can be applied at pandemic scale, in which half the population of the world would likely be infected over the course of a year or more. We would be left with other measures, now termed "nonpharmaceutical interventions," to stave off the worst effects of a pandemic until a vaccine could be produced and widely administered (4, 5). Because many of these interventions, such as closing schools or shutting down mass transit, could be very disruptive to society, it is important to use effective measures in a rational way. But which measures are most effective, and how should they be applied? Do any nonpharmaceutical interventions actually help? Until now, there has been very little systematic examination of these questions.